1. Field of the Invention
This invention pertains to multi-tap pad mount connectors that receive a primary electrical connection from a pad-mounted transformer and distribute that electrical connection to a plurality of secondary electrical conductors. More particularly, the invention relates to improvements in the electrical and mechanical connection between a multi-tap pad mount connector and the secondary connectors.
2. Description of the Related Art
In the prior art, it is known to provide a pad mounted transformer enclosure for surrounding a transformer and distributing the electrical output of the secondary side of the transformer to a plurality of secondary lines. Many of the connectors used to establish electrical continuity between the secondary side of a transformer and a plurality of secondary lines require that the ends of the secondary lines be pushed longitudinally through openings. Such insertion can be difficult if the secondary lines are frayed or have burrs. Further, the secondary lines are typically very heavy gauge aluminum or copper wires that are stiff and difficult to maneuver in the limited space of the pad mount transformer enclosure.
U.S. Pat. No. 6,203,384 discloses a multi-tap pad mount connector having multiple secondary conductor lay-in channels. Each conductor lay-in channel is provided with an adjacent obliquely angled flange. A threaded male member (a set screw) penetrates through the flange into the lay-in channel to fix a secondary conductor within the lay-in channel. One drawback of this arrangement is that the set screw tends to have a convex end where it secures the secondary conductor. The secondary conductor also has a convex shape. The two convex shapes of the set screw end and the secondary conductor form a relatively weak and insecure mechanical connection. The clamped portion of the secondary conductor tends to deform in a manner that resists secure clamping by the set screw.
Relevant electrical and building codes require that all conductive surfaces on the connector and secondary conductors be electrically insulated, even though these components are inside the pad mount transformer enclosure. In the prior art, this has been accomplished by enclosing each pad mount connector in a plastic sleeve and then inserting secondary conductors through openings in the plastic sleeve to engage the secondary electrical terminals on the connector. Working through relatively small openings in the plastic sleeve has proven awkward and time consuming. Further, the sleeve makes it difficult to assess the integrity of a connection established within the insulating sleeve by visual inspection.
A top-loading pad mount connector in accordance with the present invention includes a plurality of conductor lay-in grooves formed transversely to the length of a conductive connector body. A pivoting pressure pad is associated with each conductor lay-in groove. Each pressure pad includes a bore for receiving a fastener that passes through the pressure pad to threadably engage the connector body. A pressure pad guide surface formed on the connector body extends parallel to each fastener.
An outside surface of the pressure pad takes the form of a radius partially surrounding, and substantially parallel to the fastener-receiving bore. The pressure pad rotates between a clamping position in which a laterally projecting jaw projects over the conductor lay-in groove and an open position that uncovers the groove to permit lay-in installation of secondary conductors. Means are provided for transmitting some of the torque applied to the fastener to the pressure pad. The radiused surface of the pressure pad is configured so that tightening of the fastener moves the pressure pad toward the clamping position beyond which it is restrained from pivoting by the pressure pad guide surface. Loosening the fastener moves the pressure pad toward the open position beyond which rotation of the pressure pad is restricted by the pressure pad guide surface.
Another exemplary feature of the present invention is that the threaded bores in the connector body and the associated pressure pad guide surfaces may be angled relative to the connector body longitudinal axis. This angle serves to orient the fastener heads outwardly relative to the pad-mounted transformer and its enclosure. The outwardly oriented fastener heads are more easily accessed by electricians during installation of the secondary lines.
The jaw of the pressure pad includes a concave clamping surface which, when the pressure pad is in the clamping position, is generally aligned with and above the conductor lay-in groove. When the pressure pad is in the open position, the clamping surface is substantially perpendicular to the conductor lay-in groove and positioned out of the way to permit lay-in installation of a secondary conductor. An angled fastener and pressure pad provide a wedge-shaped conductor lay in path that facilitates laying in of the secondary conductors when the pressure pad is in the xe2x80x9copenxe2x80x9d position.
It will be appreciated by those of skill in the art that the self-aligning properties of a pressure pad in accordance with the present invention permit one hand to both align and secure the pressure pad while the other hand holds a secondary conductor in the lay-in groove. Burred, frayed or otherwise misshapen secondary conductors are guided into place by adjacent surfaces and compressed between the concave lay-in groove and clamping surface of the pressure pad. The opposed concave surfaces of the lay-in groove and jaw clamping surface provide a very strong mechanical engagement between the connector body and the received secondary conductor.
An electrical connector in accordance with the present invention also includes a clamshell insulating cover. The clamshell cover configuration allows the connections with secondary conductors to be established and inspected prior to covering the assembly. A two-part snap-together cover may also be used.
An object of the present invention is to provide a new and improved top-loading pad mount connector that permits lay-in installation of secondary conductors.
Another object of the present invention is to provide a new and improved top-loading pad mount connector to which secondary conductors may be affixed and the connections inspected prior to installation of an insulating cover.
A further object of the present invention is to provide a new and improved top-loading pad mount connector in which the secondary conductor connections have improved electrical and mechanical integrity.